QRA75.A27 Siemens Detector

Overview

The Siemens QRA75.A27 is a self-checking ultraviolet (UV) flame detector designed for the supervision of gas or oil flames and for ignition spark proving. Engineered for continuous or high-demand operation, this high-precision sensor is a critical safety component in burner management systems, ensuring reliable flame detection and preventing potential hazards during burner cycles. It is specifically designed to work with Siemens burner controls, such as the LMV5 or LME7 series, to provide electronic self-supervision of the UV cell.

Features

• Self-checking mechanism allows for continuous flame supervision by periodically testing the UV cell
• Normal sensitivity UV photodiode optimized for gas flames and blue or yellow burning oil flames
• Integrated stepper motor and shutter system to facilitate the self-supervision cycle
• Durable die-cast aluminum housing designed to survive challenging combustion environments
• Protection rating of IP65 ensures reliability and dust/water resistance in industrial settings
• Compact design with a 69 mm detector tube for flexible mounting configurations

Specifications

• Model: QRA75.A27
• Mains Voltage: AC 230 V (+10% / -15%), 50/60 Hz
• Detector Tube Length: 69 mm
• Sensitivity: Normal
• Operating Temperature: -20 C to +60 C
• Weight: Approximately 0.8 kg (1.76 lbs)
• Power Consumption: 3.2 VA
• Replacement UV Cell: AGR450240650

Applications

• Supervision of gas flames and yellow or blue burning oil flames in industrial and commercial burners
• Ignition spark proving in high-demand combustion systems
• Integration into burner management systems (BMS) for industrial furnaces and boilers
• Used in conjunction with Siemens LMV5, LME7, and LFL series burner controls
• Ideal for high-temperature and harsh environments where UV sensing is required for safety compliance